typecasting

[hitholdir]

Hello everybody,

I have an array that I calculated the sum of 10 integer elements in an array, and now I am finding the average, but it has to be of float type.
Before I found this website: http://publib.boulder.ibm.com/infocenter/comphelp/v8v101/index.jsp?topic=%2Fcom.ibm.xlcpp8a.doc%2Flanguage%2Fref%2Fkeyword_static_cast.htm
I tried implementing typecasting by doing this:

	float avg = static_cast<float>(Sum(store)/10);
	return avg;

but instead of the answer I was looking for, say, 2.4, it returned 2.
Could someone explain why does putting the parentheses only around Sum(store) work but around the whole expression doesn't?

[firedraco]

If you put it around the whole expression, you are doing integer division *first*, which means you get an integer answer. Casting the integer to a float afterwards doesn't help.

[Volatile Pulse]

An alternative method is to divide by 10.0 which makes your division become a double. To get a float, divide by 10.0F. This signifies that the type is float and will return a float as so.

To keep using the static_cast, you would want something similar to:
float avg = (static_cast<float>(Sum(store))/10);

This will force the return of Sum(store) to be a float and I believe a float divided by an integer should give you a float in return.

The division is at times a pain in the butt, but just remember, you get the highest precision as the highest precision value you put into it.
int/int will return int
int/float will return float
int/double will return double

Atleast that's how I've always looked at it. I could vary well be wrong.